In a trend of big data, a multi-duplicate manner is usually used to ensure data reliability. However, many data migration operations between nodes are usually caused when the multi-duplicate manner is used.
An RDMA (Remote Direct Memory Access) technology implements reading of data between two nodes on a network. An RDMA directly transmits data into memory of a computer through a network, and fast migrates the data from a local node to memory of a remote node without causing any influence on an operating system.
RDMA information transmitted on the network includes a destination virtual address, a memory key and the data itself. Request completion may completely be processed in user space (an arrangement is completed by using a polling user level), or is processed by using kernel memory in a case in which an application sleeps until a request is complete. By performing an RDMA operation, an application may read data from memory of a remote application or write data into the memory. A network adapter of a target host determines a memory key, and directly writes the data into an application cache.
The RDMA requires that data transmission between two servers that communicate with each other must be performed on transmitted data by using memory. If the memory is not used, data transmission cannot be performed. As a result, a delay of data transmission and a usage ratio of the memory are relatively high.